A method for bearer reservation, maintenance, and use in a communication system is performed by an intermediary function (IF) in the enterprise network. The IF processes a user plane reservation request for a flow of user plane data from a sourcing device, and determines a set of bearers to transport the flow of user plane data. The IF requests from at least one access network the determined set of bearers, and receives from the at least one access network an allocated set of bearers, wherein the allocated set of bearers comprises one or more bearers. The IF receives the flow of user plane data from the sourcing device. The IF receives an indication that at least one of the bearers in the allocated set of bearers is unavailable, and prevents at least a portion of the flow of user plane data from being transmitted over the default bearer.